A coke oven is configured by carbonization chambers and combustion chambers that are alternately provided along a coke oven battery. Heat in the combustion chamber transferred to the carbonization chamber dry distills coal charged in the carbonization chamber so as to produce coke.
In this country, because many of the coke ovens have been used for years after the construction, carbon have repeatedly adhered, grown, and been peeled off wall surfaces of the carbonization chambers in the coke ovens. Such aged coke ovens tend to have increased resistance against coke extrusion due to this repetition. The increase in resistance against extrusion may cause troubles in removing coke out of a carbonization chamber. Therefore, monitoring the state of the chamber wall in the coke oven is quite important for safe operation of the oven.
Monitoring the state of chamber walls have been conventionally performed visually, or with use of a permanent chamber width measurement device (see Patent Document 1, for example) or a permanent in-chamber observation device (see Patent Document 2, for example).
However, visual monitoring is difficult to be accurately performed even by an experienced worker, because the worker cannot closely approach the oven having in-chamber temperature as high as about 1,100° C., as well as because a coke oven is configured to have a distance to the back as long as about 15 m while having a chamber width as short as approximately 450 mm, thereby failing to secure a clear visual field.
Even in the case of monitoring with use of the permanent chamber width measurement device or the permanent in-chamber observation device, although an operator checks chamber width data and monitors chamber wall images, such monitoring in the oven is performed along with other tasks. It is, therefore, hard to constantly monitor changes in the state of chamber walls.